[Gmsh] Physical entities in mesh file format

[Geordie McBain]

2010/10/4 Simone Cassani <garetcer at gmail.com>:
> Hi,
>  i'm using gmsh to create a 3-d mesh. When i try to save it in .mesh format
> with 2.4 version, all node labels are set to 0 (i tried both the options
> physical or elementary entities) . With the nightly builds version the
> program saves only the elementary entities labels despite the option i
> choose. It's possible to save physical entities? Is there any command line
> flags to choose which kind of label save?

Not that I know of.  This question came up recently (July); see the
thread `about .mesh file format'

  http://www.geuz.org/pipermail/gmsh/2010/005674.html

Perhaps some of the considerations raised there might help you?